U.S. Pat. No. 4,543,308 describes the measurement of luminescence intensities in exposed and processed photographic film by means of a commercial emission spectrometer, utilizing monochromators on both the illumination and detection sides of the instrument.
EP-A-0 610 994, incorporated herein by reference, describes a color photographic system which uses a color photographic system in which fluorescent interlayers are positioned between red-, green- and blue-sensitive recording layer units (without any dye image-forming materials) which form silver images of substantially the same hue. The color records are read out by scanning both the fluorescent and transmission records. The image densities are read from the two fluorescent interlayers by scanning through red and green filters, and the transmission density being scanned separately.
It is well understood that fluorescent or luminescent layers need to be excited at a particular wavelength to stimulate the production of radiation at another wavelength. A scanning process using a densitometer, with an absorption filter placed in the illuminating light path for fluorescent readout, is disclosed therein.